ahmad jahan latibari

This research investigates the finger joints of pine wood (Pinus sylvestris) using polyvinyl acetate glue reinforced with cellulose nanofiber (CNF) and nanoclay particles, employing the free vibration method in free-free beams. Finger joints were created at three levels (0%, 0.4%, and 1.5%) in the middle of the samples with polyvinyl acetate adhesive containing cellulose nanofiber and nanoclay. The results indicated a significant increase in the modulus of elasticity and elastic stiffness due to the addition of both 0.4% and 1.5% of cellulose nanofiber and nanoclay. The damping factor values ​​showed a significant decrease by adding both levels of 0.4 and 1.5 cellulose nanofibers and nanoclay compared to the samples without nanoparticles. The values ​​of acoustic conversion efficiency also increased by adding both levels of 0.4 and 1.5 cellulose nanofibers and nanoclay compared to samples without nanoparticles. In general, with the increase in the percentage of use of both nanoparticles, better acoustic properties were observed in finger joints, and the effect of Cellulose Nano Fiber was greater than that of Nano clay.

From the limitations of detecting the amount of useful life remaining in the components of the structures in the conditions of use with acoustic methods is the impossibility of calculating the modulus of elasticity due to the impossibility of removing the part from the structure. Therefore, most of the classifications during use in the components of structures such as historical buildings are based on measuring the speed of sound. In this research, to calculate the local and global density with the method of pin penetration rate in wooden tie in order to calculate the amount of their remaining useful life by combining stress wave and free longitudinal vibration methods has been studied. There was no significant difference between the values of global sound velocity and global modulus of elasticity with the local results of these factors at the five tested points in each of the wooden tie.

The number of three saturated wooden tie from Iran Railway Company and with the dimensions of 15x25x260 cm, which are made of beech species (Fagus orientalis) and the density was measured by pin penetration method at 5 points of each wooden tie (50 cm distance between each point) and the average results of 5 points were compared with the results of ISO 13910 standard method. The stress wave test was carried out at the same 5 points of density determination by pin penetration rate method to determine the local modulus of elasticity and the results of each point were compared with the global modulus of elasticity of the beam. Longitudinal vibration test was also performed to calculate the damping factor values of the samples.

The results showed that there was no significant difference at the 95% level between the values calculated with both the ISO 13910 standard methods and the pin penetration rate method, and there was a favorable linear correlation between the results of the two methods. According to the results, there was no significant difference between the global sound speed of the beams and their local sound speed in any of the five measured points at the 95% level and there was a linear correlation between the values of the global sound speed and each of the five local points. There was no significant difference at the 95% level between the values of the global modulus of elasticity and the values of the local modulus of elasticity calculated in each of the five points. Also, there was a linear correlation between the values of the global modulus of elasticity and the results of the local modulus of elasticity in each of the five points. There was an exponential correlation between the values obtained from the global modulus of elasticity and the damping factor of each of the wooden tie.

The equality of density according to the ISO 13910 standard method and the nail penetration method, as well as the equality of the modulus of elasticity calculated by the stress wave method and the free longitudinal vibration method, make it possible to obtain all the data required for calculations without removing the part from the structure. The remaining strength of wooden components should be provided according to EN338 standard.

In this research, the effect of soaking process and ethanol-acetone washing as well as fermentation pre-treatment by bread yeast in Cypress (Cupressus arizonica) has been investigated. The samples were subjected to pre-treatment with bread yeast and without pre-treatment, washing with pure water and removal of extractives in organic solvent and subjected to dynamic test by forced vibration test in free-free beam. Both methods of soaking process and ethanol-acetone washing resulted in a significant decrease in density and vibration damping, while the values of acoustic conversion efficiency showed an increase. The amount of improvement of acoustic properties due to ethanol-acetone washing was more than water washing. Fermentation pretreatment increased the changes in both water washing and ethanol-acetone washing methods. The dynamic modulus of elasticity did not show any significant change water washing, ethanol-acetone washing and fermentation pretreatment. In general, the ethanol-acetone washed samples under fermentation pretreatment left the highest acoustic indices.

Nowadays, the importance of treatments such as water washing and ethanol-acetone washing to improve the acoustic properties of wood has been noticed by the makers of musical instruments. Wood extractives are in the list of those materials that often do not have a construction role, and their purposeful and correct evacuation can lighten the wood without reducing the stiffness. Carrying out pre-treatments such as fermentation with bread yeast (before water washing and ethanol-acetone washing processes) can lead to the extraction of more extractable substances from wood. In this study, the effect of water washing and ethanol-acetone washing treatments as well as fermentation pre-treatment on the acoustic properties of Ash wood (Fraxinus excelsior) has been investigated.

Ash wood species (Fraxinus excelsior) was prepared from the wood of a commercial timber and 38 small radial beams with nominal dimensions of 150×12×2 mm (longitudinal×radial×tangential) were extracted from the hardwood. After reaching the equilibrium humidity of 12% in air-conditioned conditions, the selected samples were subjected to the forced vibration test in the free-free beam in order to measure the basic physical and acoustic characteristics. After that, the initial tests were randomly divided into two groups of 19 tests. The first group without pretreatment and the second group with fermentation pretreatment were placed in the process of removing the extractives by water and then by ethanol-acetone mixture. After each step of water washing and removing the extractive substances soluble in ethanol-acetone mixture, the forced vibration test in the free-free beam was performed on the samples and the acoustic properties of the samples were measured.

Water washing without pretreatment with bread yeast caused a slight decrease and with pretreatment, it caused a significant decrease in density values (respectively: 1.75 and 7.39%). While the process of removing extractives (with and without pretreatment) by ethanol-acetone mixture caused a significant decrease in density values (Respectively: 2.27 and 8.71%). The modulus of elasticity values showed a significant decrease due to water washing without pretreatment and with pretreatment. (Respectively: 11.37 and 16.47%). The process of removing the extractives by ethanol-acetone mixture also resulted in a significant decrease in the modulus of elasticity values in untreated and pretreated samples (Respectively: 13.87 and 20.93%). Water washing without pre-treatment with bread yeast and with pre-treatment has caused a significant decrease in the values of damping factor, among which the pre-treated samples had a greater percentage of drop in the values of damping factor (Respectively: 13/87 and 20.93%). The process of removing the extractive materials by ethanol-acetone mixture as washing has caused a significant decrease in the damping factor values, which among the pre-treated samples showed a greater percentage drop in the values resulting from this property (Respectively: 3.03 and 18.01%). In this factor, the process of removing the extractive substances soluble in ethanol-acetone mixture (with and without pretreatment) has resulted in a greater drop in damping values (respectively: 6.67% and 20.85%). Acoustic conversion efficiency due to water washing process without pretreatment with baker's yeast caused a slight increase, while pretreatment caused a significant increase in acoustic conversion efficiency values (Respectively: 0.44 and 25.24%). The process of removing extractive materials by ethanol-acetone mixture also caused a significant increase in the acoustic conversion efficiency values, which among the pre-treated samples showed a higher growth percentage in the values of this characteristic (Respectively: 3.41 and 28.90%). Both water washing methods and ethanol-acetone mixture washing were effective in improving the physical (density) and acoustic properties (modulus-elasticity, damping and acoustic conversion efficiency). Meanwhile, the effect of ethanol-acetone mixture washing was more than the effect of water washing. Fermentation pretreatment with bread yeast improved the performance of water washing and ethanol-acetone mixture washing treatments.

Plant extractives show unique properties. They impart colors and change the color of wood and generates attractive appearance. Since early days, societies have been utilizing plant extractives in industrial, medical and even as fungicides and biocides. In early times this application was based on the professional experiences, but as the sciences were advanced, then the technical and experimental identification and utilization was employed. In general, people look at walnut tree wood and fruit as its economic values. However, scientific research has proved the values of walnut tree extractives. In this study the chemical composition of walnut tree extractives and its variation in two periods of spring and summer as well as the impact of the drying on quantity and quality of the extractive components are investigated.

Walnut tree leaves from a selected location of an old walnut tree (100 years old) in mountain region of Karaj were collected in spring and summer. One part of the samples was air dried and another portion was used at green moisture condition. Totally four samples were obtained. Ethanol-acetone extraction was according to Tappi T204-05 procedure. The extractive was identified using GC-MASS spectroscopy and the chemical components in the extractives were identified and tabulated. 

The results revealed that the dried leaves contain fewer chemical compounds compared to green samples which can be an indication that some of the compounds in green sample are volatile and vaporize upon drying. Furthermore, the extractives chemical composition and content varies between spring and summer samples. The major chemical compounds identified were 2-methylneptaline, tri-decan, tetradecan, 2,3-dimethyl naptaline and methylcyclobenzen.

The results indicated the seasonal variation of walnut tree extractives. These is also considerable variation in wet and dry samples which can be attributed to the presence of volatile compounds. The odor of walnut leaves is the consequence of existence of such volatile extractives. The absence of some of the compounds in summer samples indicate the seasonal changes of the extractives.

Poly vinyl acetate (PVAC) adhesive is one of the most important adhesives in wood and furniture industry, which has many advantages such as low cost, environment friendliness and non-toxicity. However, it has some disadvantages such as low water resistance and poor boning strength. In this study, the effect of nano silica (NS) on the properties of poly vinyl acetate adhesive was investigated. The adhesive formulation with different NS contents (2, 3 and 4%) was added to the PVAC. The structure of the prepared adhesive samples was studied by FT-IR and XRD. We used the wood of Acer tree (Acer cappadocicum) to make joints in this study. Two standards of D882 and ASTM D905 were used for tensile and shear tests, respectively. Results showed that adding NS to PVAC enhanced the tensile strength of films. For example, the tensile strength of prepared films was increased by 30% after adding 4% of NS. Moreover, shear strength test showed that NS up to 3% can improve PVAC bond strength. Viscosity results showed that increasing the weight of NS up to 3% to PVAC glue lead to an increase following a decrease in the viscosity

Various corrugated board making units operate in a wide range from small workshops to large industrial units in the country. These units possess the necessary conditions to play an effective role in economic growth, job creation and development of export markets. Introducing the components and sub-components that affect the sustainability of production in this industry can be a roadmap for the business activities of those interested in this type of business. The purpose of this research is to identify and prioritize the components and sub-components of production sustainability in corrugated board making industries, to determine their current position by evaluating the different operations management activities and monitoring sustainable production performance in order to achieve the desired levels of production sustainability of carton manufacturing units. By studying and reviewing the available literature and sources, seven main components affecting the sustainability of production in the corrugated board making industry, namely regulations, economic, environmental, technological, social, human, material and product, and 43 sub-components were identified by setting up a researcher made questionnaire. The questionnaire construction and distribution among the managers and experts of the industry with the aim of influencing each component and sub-component on production stability and their current status were investigated and the results were analyzed with the relevant tests. Based on the findings of the research, all the components affecting the sustainability of production based on the standard coefficients and significance of the structural equations as well as the predictive criterion of verification and quality of the data presented with the redundancy index with cross-validity have the necessary validity for prediction. The prioritization of components based on the rank average and the distance to the sustainability of the economic, material, product and technological components showed the lowest distance and the environmental components, rules and regulations showed the greatest distance to achieve sustainability in the carton industry. Therefore, in order to achieve the sustainability of production in the industry of environmental components, laws and regulations should be paid more attention. Corrugated board making companies can take advantage of the results of this research in order to achieve sustainable production. Therefore, by examining and analyzing their current situation, they determine the position of their organization in terms of the components and sub-components of production sustainability, and then to achieve a better position, they fix the deficiencies and related problems by determining and implementing projects.

In this study, the ability to bleaching hemicellulose-deinked pulp was investigated in comparison with conventional chemical method. Initially, the mixed recycled pulp pre-treated with hemicellulase enzyme at different levels of usage, treatment time and pH values (under other constant process conditions) was bleached and experimental runs included H2T3 (usage 0.2% (based on dry weight of recycled pulp); Treatment time 60 minutes and pH range 6.5-7) and H3T2 (usage 0.5% (based on dry weight of recycled pulp); Treatment time 50 minutes and pH range 6.5-7) were selected as the best treatments. Then, the selected pulps were bleached using hydrogen peroxide under constant process conditions and their bleachability was compared with conventional chemical pulp. Based on the results achieved, the bleachability of hemicellulose-deinked pulps was better than that of chemically deinked pulp, and the resulting papers had a higher brightness and whiteness as well as less yellowness, but the opacity of these papers was decreased during bleaching. Also, pre-treated pulps with hemicellulase showed the papers with higher tensile and burst indices after bleaching stage so that for H2T3 and H3T2 enzymatic runs, the increase in tensile index was 13.22% and 12.59%, and in burst index was 3.66% and 6.22%, respectively. While the tensile and burst indices for chemically deinked pulp after bleaching was improved by 10.17% and 16%, respectively. Also, the reduction in paper tear index for H2T3 and H3T2 enzymatic runs after bleaching was 12.45% and 8.06%, respectively, compared to chemically deinked pulp (4.44%). Based on the overall results obtained by comparing the quality properties of papers made from different pulps bleached with hydrogen peroxide, H2T3 run has resulted in more bleachability and much better optical and strength properties.

This study aims to identify the expectations and preferences of consumers of home and office furniture using nonparametric tests. The statistical population consists of customers of the home and office wood furniture industry in Tehran and a stratified sampling method was used in this study. Cochran formula was used to determine the sample size. To determine the effective indicators, the researcher studied the available resources and the Van et al.’s model as the basic model and conducted a factor analysis to design the conceptual model of the research. Using a field research, the student t-test and Friedman test, she examined the relationship between consumer preferences and 5 factors and 17 subindices.

The reliability of the questionnaire was confirmed by the data obtained from 100 questionnaires using Cronbach's alpha. The results of descriptive statistics indicated that the mean of all the indices was at an average level. The minimum and maximum values and the standard deviation showed that there were no outliers. The results of inferential statistics in SPSS software indicated that as the significance level for Kolmogorov-Smirnov test was greater than 5%, all variables are assumed to be normally distributed. The results indicated a significant relationship between all indicators and consumer preferences regarding home and office furniture. The results of the one-sample t-test indicated that consumers consider corporate responsibility factors, product and vendor’s characteristics and internal factors above average while they consider environmental and safety factors at the average level in the purchase of home and office furniture. The results of the Friedman test indicated the priorities as follows: vendor’s characteristics, internal factors, corporate responsibility factors, product characteristics and safety and environmental characteristics.

The first step in feasibility study of any national mega projects in energy sector is the investigation on the production potential and evaluate the market demand for the product. The success rate of a biofuel project after forecasting supply and demand depends on choosing the appropriate place to produce. In this respect, factors such as the selection of appropriate production site, environmental, technical, economic and social are among major issues. In this study, autoregressive integrated moving average (ARIMA) model was used for the prediction of bioethanol demand in five sceneries; E5, E10, E15, E20 and E30. The time period up to 1412 is foreseen. The data on agricultural wastes and the present and future potentials for the bioethanol production in different provinces is analyzed. The results indicate that, the average daily consumption of gasoline will increase to 136,922 million liters per day as we reach 1412.The study also shows that there exists the potential for the production of 18.16 million liters of bioethanol which can fulfill the requirement of E5 and E10 by 1412. If we want to implement the E20 and E30 scenario in the country, it is necessary to increase the production of 7 selected products in this research, in the provinces of Khuzestan, Fars, Khorasan Razavi, Golestan, Isfahan, Mazandaran, Tehran, Qazvin and Alborz and Gilan by 62.2 million tons per year by 1412, And consider the effective factor in the success of the project, namely the support of the government and legislators for national mega projects.

Natural disasters and the need to facilitate and relief the consequences of such disasters has initiated global crisis in its respective management. Reducing the variabilities of inhabitants requires the integrated system to battle against such devastations and crises. This research presents the application of Delfi method to identify the influential factors on risk management model risk management model for the wooden structures in Iran. The statistical population of the study consisted of the academic and organizational experts. A total of 30 individuals were interviewed using a purposive non-random sampling technique as well as data adequacy and saturation principle. A semi-structured interview was used to collect the required data. Delfi method was applied for data analysis in qualitative section. The results indicated that 43 risk factors are influential in wooden structures which can be classified as internal and external risks. Among these risk factors, 11 are considered as the major factors which influences the application of risk management in construction of wood structures in earthquake prone regions of Iran.

The paper recycling industry consumes a significant amount of fresh water in its processes. Complete or major treatment of generated effluent is always one of the priority and policies of industries. In this study, aluminum electrodes with dimensions of 2*150*20 mm were used and by adding hydrogen peroxide to the effluent and performing electro-fenton reaction, the residual concentration of pollutant was measured by spectrophotometer. After obtaining the optimum values of voltage, agitator speed, reaction time, pH, hydrogen peroxide concentration, molar ratio of hydrogen peroxide to iron sulfate and distance between electrodes, the percentage of COD removal was calculated. COD reduction efficiency percent for electro-fenton reaction was 95.50% also the optimized conditions were as follows, voltage: 6 volts, pH: 2, stirring speed: 300 rpm, concentration of hydrogen peroxide: 1000 mg/L, distance between electrodes:3 cm, molar ratio of hydrogen peroxide to iron sulfate:1/4 and  reaction time: 90 minutes. The results showed that the electro-fenton method can be used successfully for wastewater treatment of paper recycling industries.

Reaching to the technology of acoustical Tomography and imaging, this project was ordered for facilitating the work for green space researchers and managers in urban standing trees. Comparing the sensors and micro-second timers with those of a certified European device in radial to tangential and longitudinal directions showed a good agreement for the Iranian made device. So, a new horizon was opened for the researchers of this approach supported by the local scientific knowledge and technology. Holding this technology, the selected trees concerning the collar defect symptoms were firstly inspected visually, then the visual accuracy was monitored by sonic tomography. Some trees were extremely defected internally, while the visual inspection showed their intactness (9 from 23). Meanwhile some trees holding visually defect signs were proved to be intact after carrying the tomography images (up to 10 from 53). It is concluded that the visual tree defect inspection is not satisfactory for saving or omitting the individual and these kinds of decision makings must be supported by the methods showing the hidden discontinuities.

This study was carried out to investigate the effect of storage time and moisture content of bagasse on the physical and mechanical properties of particleboard. For this purpose, wet depitting bagasse was used and samples were maintained in bailing storage method. In this study, was applied 4 storage times (1.5, 3, 4.5 and 6 months) and 2 moisture content of Bagasse (45% and 55%). According to these variables, particleboards were made. Also chemical properties (pH, acid and alkaline buffering capacity) of Bagasse were determined. The mechanical and physical properties of the boards were measured and statistically analyzed using factorial experiment and complete randomized design. Then Duncan multiple range test was used for grouping of the averages. The results revealed that with decreasing of Bagasse moisture content, Bagasse sample pH and acid buffering capacity were decreased and increased, respectively. Also bending properties and thickness swelling after 24 hours immersion of the boards were improved. With increasing of storage time, the chemical properties of Bagasse tend to be alkaline, and the minimum of board internal bond strength was obtained in 1.5 month storage time. The physical properties of boards were improved with increasing of storage time

The effect of compounding process applying two methods of one and two step mixing on the properties of nanocomposite is investigated. Nanocomposites were produced using polypropylene, cellulosic fibers, MAPP and nanolay as reinforcement. 1.5 and 3% MAPP and 0,2, and 4% nanoclay were used as the variable factor and 20% fibers was used. Melt flow index was measured on compounds produced using one or two steps mixing. Either compounds were mixed with fibers and MAPP and then the test specimens were made and tested according to ASTM test procedures. The results revealed that the two steps mixing increased the mechanical properties. The melt flow index of one step mixing was lower and the melt flow index of initial mixing of polypropylene with nanoclay was very high and it was reduced after compounding with fibers and MAPP. The results revealed that at higher dosages of the nanoclay tensile and bending modulus of the composite increased and tensile strength and modulus of rupture decreased.

At this research, the influence of Multi Walled Carbon Nano Tubes (Non-functionalized and functionalized) on mechanical properties of polypropylene – old corrugated container (OCC) fibers composites was investigated. OCC fibers polypropylene composites were prepared using 20% OCC fibers, 80% polypropylene and 3% MAPP. Three levels of multi walled carbon nano tubes (0% - 0.5% - 1%) were added. Acidic oxidation method was used to functionalize the MWCNTs. Mechanical properties were measured as defined in ASTM testing methods. The results indicated that at higher dosage of MWCNTs, the tensile strength properties of the composite were improved but the influence of the functionalizing was not statisitaclly significant. The bending strength and elasticity as wellas the izod impact were increased as the higher amount of nanotubes were added to the composite. Scanning Electron Microscopes showed the development of bonding between the composite components. Compostes without coupling agent showed lower bonding strength between polypropylene and fiber as indicated by fiber pull out. However, in the composites containing coupling agent, the fiber fracture was observed.

Enzymatic deinking has been suggested as an environmentally friendly alternative to complement and replace for conventional chemical deinking. In the present research, the effect of hemicellulase from Aspergillus niger has been evaluated on paper quality of mixed 70% old newspaper (ONP) and 30% old magazine (OMG) pulp. Hemicellulose was used at different charges of 0.1 (H1), 0.2 (H2), 0.5 (H3) and 1 (H4) percentages based on oven dry weight of pulp and different times of 40 (T1), 50 (T2), and (T3) under constant conditions of %10 consistency, temperature 55-60 °C at pH range of 6.5-7 and then the pulps were washed and floated. The results showed that compared to undeinked pulp (C1) and chemical deinked pulp (C2), papers with higher brightness, whiteness and appropriate opacity could be achieved at % 0.2 enzyme concentration and duration time of 60 min (H2T3) and also % 0.5 enzyme concentration and duration time of 50 min (H3T2). Also, the results of assessments indicate that the highest tensile index (32.271 and 30.017 Nm/g), breaking length (3.131 and 2.974 km) and stiffness (3.94 and 4.12 mN) were observed in treatments of H2T3 and H3T3, and the highest tear index (7.688 and 7.34 mN.m2/g) was observed in treatments of H1T1 andH1T2 respectively. These results are more desirable than paper produced with treatment samples of C1 and C2. In general, achieved results from this research indicate that hemicellulase has a good potential to improve the quality of mixed recycled ONP and OMG waste papers vs. standard conventional system.

Application of cellulosic fibers and minerals of deinked waste paper sludge has a great impression on utilization and characteristics of final product. This study was designed to produce use gypsum-fiber board from the DIP sludge. The gypsum: sludge ratio was considered as 100:0, 90:10, 80:20, 70:30 and 60:40. Two types of gypsum boards were prepared with fixed 12 mm thickness and cold pressing time of 10 and 20 minutes at 30 kg/cm2. The results revealed that, regarding the fact that the DIP sludge contains a variety of short fibers with excessive amount of minerals, increasing the sludge loading could affect the compatibility of gypsum and sludge. The effect of sludge on physical and mechanical properties of gypsum fiber boards was significant to probability of 99%, in a way that maximum water absorption, maximum thickness swelling and minimum density of the boards for the treatment of 40:60 percent of gypsum to sludge was gained as follows in respect: 29.7%, 2.15 % and 0.66 g/cm3. On the other hand, MOR and MOE for board with gypsum: sludge ratio of 70:30 were gained 1.765MPa and 1.598 GPa, respectively. The effect of pressing time on physical properties of gypsum fiberboard was not significant at the probability of 95%. According to the obtained results, it has been suggested that such boards could be used in covering and ceiling isolating applications.

Strength properties and the yield of soda and soda-ethanol pulps produced using hornbeam, beech and poplar woods were investigated. Soda pulps were produced applying 20% active alkali and the soda-ethanol pulps were made using 10% active alkali and 50% ethanol. The pulping temperature was constant at 175 C and the soda pulping time was selected at 120 minutes and the soda-ethanol pulping times were 120 and 180 minutes. The highest accepted pulping yield at 58.54% was reached using soda pulping on poplar wood and the lowest yield (49.29%) was related to soda-ethanol pulp produced from beech wood applying 180 minutes pulping time. The accepted yield of soda-ethanol pulping was low, but the kappa numbers of these pulps were almost 20 units lower than soda pulps. The strength properties of soda-ethanol pulps were superior to soda pulps and the difference was statistically significant at 99% confidence level. The results of this study indicated that the delignification of soda-ethanol pulping process is faster than soda pulping from the selected hardwoods especially poplar wood.

Among the forest diseases, fungi are the most important factors that cause irreparable losses to the wood in standing trees and logs. Fungi are the cause of contamination and decay of trees and timbers in forest or in the stock of factories. Decayed woods are one of the biomass resources and a great amount of decayed woods in the forests are not viable. In this study some experiments were conducted in order to investigate the effect of Coriolus versicolor decay on compounds obtained from beech wood (Fagus orientalis L.) pyrolysis and preparation of various and valuable chemicals. Separation and identification of chemical compounds in sound wood and decayed wood of beech was conducted by using pyrolysis method at 500° C and in nitrogen atmosphere. Separation and identification of extracted chemical compounds was carried out using sailylation of these compounds by N, O-bis (trimethylsilyl) trifluoroacetamide and also using Gas Chromatography and Mass Spectrometry method. Totally, 23 compounds were identified in sound beech wood which most of these compounds, in this temperature, are related to 2,6-dimethoxyphenol and 3-hidroxy-4-methoxy benzoic acid; and 31 compounds were detected in decayed beech wood that most of them are related to Cyclononasiloxane octadecamethy and 4-(3,4-Dimethoxybenzylidene)-1-(4-nitrophenyl) and also 17 compounds were detected the same in sound and decayed wood.

In this research the effect of softwood cellulose fibers surface characteristics on mechanical properties of cellulose fibers / polypropylene composite (W.P.C) was studied. The fibers were refined to modify the surface characteristics and reach four different freeness levels (11, 14, 17 and 21 °SR). Then the fibers were mixed with polypropylene using pre-determined levels of 20% fibers and 77% polypropylene and 3% MAPP and samples were made. The results revealed that refining the fibers will change the strength of the composites. Statistical analysis should that the impact of the different freeness levels statistically influenced the strength at 99% confidence level. The highest strength levels were reached using fibers with the freeness level of 14 oSR.

The effect of lamination and adhesive coverage rate in layered products made from Poplar wood was studied The effect of lamination and adhesive coverage rate in layered products made from Poplar wood was studied by non-destructive free vibration test. 120 samples with nominal dimensions of 2. 5×2. 5×45 cm without any obvious deficiencies were selected and free flexural vibration in free-free bars were performed for testing them. Samples were longitudinal cut in three thinner tangential layers and jointed together again using Poly Vinyl Acetate glue. The specimens were divided into four groups according to adhesive coverage rates، which one group was fully glued and 3 groups were carrying some glue deficiencies in different rates. Manipulated samples were tried again in above mentioned test. Results indicated that shear moduli compare to modulus of elasticity is a more sensitive parameter to evaluate glue efficiency in laminated beams but concerns remained due to blind points in flexural vibration nondestructive method.

Old corrugated container (OCC) recycling generates large volume of effluent which is heavily loaded with pollutants. Its treatment is very difficult and complicated due to the presence of various pollutants and certain chemical with complicated structure. In this study، the treatment of OCC recycling effluent using nano TiO2 was investigated and the treated effluent parameters such as COD، TDS، TSS، TS، EC and turbidity were measured. Nano TiO2 was applied at 0. 5%، 1%، 1. 5% of the effluent volume and the pH was adjusted at either 5، 9 or 7. 3 (as received from mill). The results showed that the nano TiO2 and pH are effective on all of the parameters and the effect was statistically significant at 99%، but the effect of variables on EC was not measured statistically significant. The effect of pH on all of parameter was statistically significant at 99% expect on EC. Optimum condition was pH=9 and the dosage of nano TiO2= 0. 5% and 1%. At this treatment condition، COD، TDS، TSS، TS and turbidity were reduced by 47. 5، 38. 7، 98، 70. 4، and 97. 7 % respectively

The properties of alkaline sulfite anthraquinone (AS/AQ) pulp from old corrugated container (OCC) was studied. In each trial 100 grams (based on dry weigth) of OCC and 18% active alkali was used. Three levels of anthraquinone (0.0.1 and 0.2% based on dry weigth of the OCC) and two pulping times (120 and 150 minutes at maximum pulping temperature) were applied. Pulping temperature, Na2So3/NaOH ratio and liquor to OCC ratio at 170ºC,30/70 and 8/1 respectively were constant in all pulping trials. The results showed that the effect of pulping temperature on pulp kappa number, AQ on pulping yield and kappa number and the interactive effect of time and AQ on pulp yield and kappa number were statistically significant at 99% level. The highest yield was reached applying pulping condition of 18% active alkali,pulping time of 150 minutes pulping time without the addition of AQ and the lowest kappa number was related to pulps produced applying 18% active alkali, 0.2% AQ and 150 minutes pulping time. The results of pulp strength measurements revealed that pulp produced applying 18% active alkali, 150 minutes pulping time without AQ exhibited the highest tensile strength index at 24.6 N.m/g and the highest tear strength index at 10.54 mN.m2/g was related to pulp produced applying 18% active alkali, 150 minutes time and 0.2% AQ. Pulps produced applying 18% active alkali, 150 minutes pulping time and 0.1% AQ was selected for elemental chlorine free (ECF) bleaching applying D0EPD1 bleaching sequence and kappa factor of 0.35. The brightness, opacity and yellowness of the bleached pulp were determined as 82.6%, 80.22% and 5.64% respectively. The bleaching yield was measured as 92.1% (based in the dry weigth of unbleached pulp) and the tensile strength and tear strength indices of bleached pulp were 17.88 N.m/g and 10.48 mN.m /g respectively.

In this investigation، the surface chemical properties of the beech wood layers were characterized and the impact of drying condition on the strength of the bond was examined. Defect free beech logs were harvested and then the layers were prepared. The moisture content of the specimens were adjusted at 30، 40 and 50% (dry basis) and then the specimens were air dried under the environment of 30% relative humidity and 21ºC to reach the equilibrium moisture content of about 10% (dry basis). The pH and buffering capacity of the surface layer and the layer 0. 5 mm underneath the surface were measured. The dried specimens were bonded using urea-formaldehyde resin and the tensile strength and wood failure were measured using relevant ASTM method. The results showed that as the moisture content prior to air drying was increased، the tensile strength was reduced، but the effect of this variable on tensile strength was not statistically significant. However، the effect of moisture content on wood failure was statistically significant at 99% significance level. The effect of the pH of the under layer on both tensile strength and wood failure was statistically significant at 95%. As the moisture content of the wood increased، the pH of the surface layer increased and the strength of the bond with urea-formaldehyde resin was deteriorated. At higher initial moisture of the wood، the alkaline buffering capacity of the surface layer was lower and its effect of the strength was not statistically significant، but it was significant on wood failure at 99% level. The alkaline buffering capacity of under layer was also changed and statistically affected the bond strength and wood failure at 95% level. The higher alkaline buffering capacity of the under layer adversely affected the tensile strength of the bond. The lowest acid buffering capacity was measured from specimens with 40% initial moisture content and as the acid buffering capacity was increased، the tensile strength was reduced and the wood failure was higher. The impact of surface layer acid buffering capacity on tensile strength was on statistically significant، but on wood failure was statistically significant at 99% level.